Neuroprotective Effects of Raloxifene on Aβ25-35-induced Damages in PC12 Cells via Mitogen-activated Protein Kinase Signaling Pathway

Objective To investigate the neuroprotective effects and the mechanism of this protection of raloxifene (RLX), a selective estrogen receptor modulator. Methods MTT assay and flow cytometry with annexin V-FITC/PI staining were performed to evaluate the neuroprotective effects of RLX on Ab25-35 -induced toxicity. The potential mechanisms were studied by Western blotting in cultured rat pheochromocytoma cells (PC12 cells). Results RLX(1 000 nmol/L), in combination with Ab25-35 (30 mmol/L), increased the cell viability (P<0.001), and reduced the number of apoptotic cells (P<0.05). RLX attenuated Ab25-35-induced loss of Dym (P<0.01). The changing of Dym was similar to the variation of apoptosis. PD98059 (inhibitor of ERK1/2) inhibited the effects of RLX on cell viability and phosphorylation of cleaved caspase-9. No significant difference of cell viability or phosphorylation of cleaved caspase-9 had been found when PC12 cells were incubated with SB203580 (inhibitor of p38MAPK) or SP600125 (inhibitor of JNK). Ab25-35 induced a time-dependent phosphorylation of p38MAPK and JNK. In PC12 cells treated solely with RLX, ERK1/2 was activated (P<0.01). In PC12 cells treated with Ab25-35 and RLX, Ab25-35-induced phosphorylation of p38MAPK and JNK were inhibited (P<0.01 and P<0.001, respectively). Conclusion RLX inhibited Ab25-35-induced cell apoptosis by activating the ERK1/2 pathway in PC12 cells. RLX also attenuated Ab25-35-induced activation of p38MAPK and JNK. The mitochondria pathway was involved in this inhibitory effect.     

Study on the Protective Effects and Mechanisms of Dendrobium Nobile Lindle. Alkaloids on PC12 Cells induced by Aβ25-35

Objective：This study was designed to investigate the protective effect of Dendrobium nobile Lindle. Alkaloids （DNLA） on the oxidative stress and apoptosis of PC12 cells induced by Aβ25-35,and further explore its potential mechanisms. Methods：PC12 cells were divided into 5 groups：control group,model group（10 μmol·L-1Aβ25-35）,DNLA-L group（0.035 mg·L-1 DNLA+10 μmol·L-1 Aβ25-35）,DNLA-M group （0.35 mg·L-1 DNLA+10 μmol·L-1 Aβ25-35）, DNLA-H group（ 3.5 mg·L-1 DNLA+10 μmol·L-1 Aβ25-35）. The cells were cultured in vitro and treated with Aβ25-35 for 24 h to induce PC12 after 6 hDNLA（ 0.035~3.5 mg·L-1） exposure. MTT assay was used to evaluate the effect of DNLA on cell viability induced by Aβ25-35,meanwhile Annexin V/PI staining by flow cytometry was used to detect apoptotic cells. Based on the identifi cation on that DNLA have antiapoptosis function towards that model,do research on effects of DNLA on oxidative stress induced byAβ25-35in PC12 cells by measuring intracellular ROS level,GSH level and SOD activity. Inverted immunofl uorescence microscopy was used to examine the effect of DNLA on mitochondrial membrane potential （MMP） stained with JC-1. Bax,Bcl-2,cleaved-caspase-9 and cleaved-caspase-3 expression level,key proteins of mitochondrial apoptotic pathway,were detected by Western blot,respectively. Results：Compared with control group,the cell viability was markedly decreased and the apoptosis showed notable increase in model group;exposure of cells to Aβ25-35 for 24 h elicited ROS production, while SOD activity,GSH expression level and MMP were markadly decreased,respectively;the protein expression of Bax,cleaved-caspase-9 and cleaved-caspase-3 were signifi cantly increased and the protein expression of Bcl-2 were decreased. However,compared with model,the cell viability of DNLA-M and DNLA-H was signifi cantly increased,and the apoptotic death was markedly decreased;ROS production was signifi cantly reduced,as well as SOD activation;on the other hand,pretreatment with DNLA at the concentration of 3.5 mg·L-1 dramatically enhanced both GSH content and MMP;the level of apoptosis relate protein Bax,cleaved-caspase-9 and cleaved-caspase-3 were significantly reduced;the protein expression of Bcl-2 was notably increased. Conclusions：Under the experimental conditions,DNLA have signifi cant inhabitation function on the apoptosis of PC12 cells induced by Aβ25-35,and its protential mechanism can be related to reducing the level of oxidative stress to inhibit mitochondrial apoptosisrelated protein expression.     

Protective effects and mechanism of Panax Notoginseng saponins on oxidative stress-induced damage and apoptosis of rabbit bone marrow stromal cells

Objective: To investigate the effects and possible mechanism of Panax Notoginseng saponins (PNS) on oxidative stress-induced damage and apoptosis in bone marrow stromal cells (BMSCs).Methods: BMSCs were isolated and cultured from 2-month-old New Zealand rabbits by the density gradient centrifugation combined with adherent method.The third passage cells were used for subsequent experiments.Oxidative stress was induced in cultured BMSCs by H2O2 (0.1 mmol/L).BMSCs were pretreated with 25-200 μg/mL PNS for 4 h before H2O2 treatment.Proliferation of BMSCs was observed using MTT assay.Alkaline phosphatase (ALP) activity,as an index of early osteoblastic differentiation,was determined with an ALP assay kit.Flow cytometry was used to observe the apoptosis of BMSCs by staining with annexinV-FITC/ propidium iodide.Oxidative stress level was examined by reactive oxygen species (ROS) assay.The protein expressions of Bax,Bcl-2 and Caspase-3 in BMSCs were analyzed by Western blotting.Results: PNS had different concentrationdependent effects on proliferation and osteoblast differentiation of BMSCs induced by H2O2.A PNS concentration of 100 μg/mL was determined as the optimal effective concentration.PNS markedly attenuated H2O2-induced apoptosis rate from 41.91% to 14.67% (P0.01).PNS significantly decreased ROS level induced by H2O2 (P0.01).Furthermore,pretreatment with PNS significantly reversed H2O2-induced inhibition of Bcl-2 expression and augmentation of Bax and Caspase-3 expression (P0.01).Conclusion: PNS had a protective effect on oxidative stress-induced damage and apoptosis in cultured rabbit BMSCs through scavenging ROS and regulating the Bcl-2/Bax pathway.     

Effects of advanced glycation end products on renal fibrosis and oxidative stress in cultured NRK-49F cells

Background Advanced glycation end products （AGEs） play a critical role in the development of diabetic nephropathy. Reactive oxygen species （ROS） may play a critical role in AGEs induced growth factor expression. In this study, the effects of AGEs on transforming growth factor β1 （TGF-β1）, connective tissue growth factor （CTGF） and fibronectin （Fn） mRNA expression and oxidative stress in cultured NRK-49F cells were examined. Methods NRK-49F cells were incubated with medium containing different doses of AGEs （50, 100 or 200 μg/ml） for 24 hours, or with AGEs 100 μg/ml for different times （0, 12, 24 or 48 hours）. Cells in the serum-free medium or medium containing 25 mmol/L glucose were controls. Cells were treated with 25 mmol/L glucose and 100 μg/ml AGEs for 24 hours to determine the effects between AGEs and glucose. We clarified the role of antioxidant by pretreating cells with N-acetylcysteine （10 mmol/L）, ginkgo biloba extract （50 or 100 mg/L） for 24 hours and with 100 μg/ml AGEs for further 24 hours. Alamarblue dye assay was used to analyze cell growth; intracellular ROS generation was measured by flow cytometry; intracellular glutathione by fluorescence spectrophotometry; expressions of TGF-β1, CTGF and Fn mRNA by semiquantitative RT-PCR. Results AGEs significantly increased the expressions of TGF-β1, CTGF, Fn mRNA and intracellular ROS generation, and decreased the glutathion level in NRK-49F cells in dose- and time-dependent manners. High glucose and AGEs together significantly increased the expression of TGF-β1, CTGF and Fn mRNA, compared with AGEs and high glucose separately. Preincubation with N-acetylcysteine or ginkgo biloba extract increased GSH level, suppressed AGEs-induced oxidative stress and TGF-β1, CTGF and Fn mRNA overexpression. Conclusions AGEs can significantly increase expression of TGF-β1, CTGF, Fn mRNA in NRK-49F cells through enhancement of oxidative stress. The accumulation of AGEs may play a pivotal role in the pathogenesis of tubulointerstitial fibrosis in diabetic nephropathy. Suppression of AGEs induced TGF-β1, CTGF and Fn mRNA overexpression in renal fibroblasts through inhibition of oxidative stress may be a mechanism underlying effect of ginkgo biloba extract in diabetic nephropathy. In addition, antioxidant therapy may help prevent AGEs accumulation and its induced damage.     

Set up Alzheimer＇s Disease Cell Apoptosis Model with PC-12 Cell Induced by Aβ25-35

Objective: To prepare an apoptosis cell model of Alzheimer Disease ( AD ) by PC-12 cells treated with β-amyloid protein (Aβ). Methods: PC-12 cells were incubated with differ-ent concentrations of Aβ25-35 for different duration in vitro. The cell viability was detected by MTT as-say. Morphological features of apoptosis were analyzed with Hoechst 33258/Prorlidium iodide dual staining, The level of intracellular free calcium ([Ca^2 ]i) was calculated by Fura-2 / AM fluorescence ratio imaging. Results: ① The viability of PC-12 cells was significantly decreased in prolrrrtion to concentration of Aβ25-35 and duration of exposure to Aβ25-35. ②The apoplotic cells appeared in a time and concentration-dependent manner, and the maximal apoptosis happened at 48 h after execute to 20μmol/ L of Aβ25-35 and 36 h to 30μmol/ L. Cell death reached the peak at 12-24 h later than the apoptotic peak. ③([Ca^2 ]i) of PC-12 cells was increased in prolrrrtion to duration of exposure to the same concentration of Aβ25-35. The time of the highest increase rate of [Ca^2 ]i was about 12 h earlier than that of apoptosis. Conclusion : An AD cell model using the PC-12 cells induced with Aβ25-35 displays aseries of chanqes related to apoptosis, which may be related to elevation of [Ca^2 ]i.     

Quercetin in combating H2O2 induced early cell apoptosis and mitochondrial damage to normal human keratinocytes

Background Oxidative stress plays an important role in the pathogenesis of epidermal diseases. This study aimed to investigate the effects of quercetin on the anti-oxidative response and on mitochondrial protection in cultured normal human keratinocytes. Methods Cultured HaCaT cells were treated with different concentrations of H202 （0, 50, 100, 250, 500 pmol/L） for different periods of time （0.5, 1, 2, 4 hours） to establish an oxidative stress model. The cultured HaCaT cells were randomly assigned to control, H2O2, and quercetin＋H2O2 groups. For the quercetin groups, the cells were treated with different concentrations of quercetin （0, 10, 25, 50 umol/L） before exposure to H2O2. Morphological changes of the cells were observed under an inverted microscope and an electron microscope. The cell viability was detected by the MIF method. The cell apoptosis （AnnexinV/propidium iodide double stain） and mitochondrial membrane potential （△ψm） changes were detected by flow cytometry. Results An oxidative stress model of HaCaT cells was established under a suitable concentration （250 umol/L） and treated time of H2O2 （2 hours）. The cell viability and △ψm decreased in a concentration-dependent and time-dependent manner while the percentage of apoptotic cells significantly increased in the H2O2 groups compared with the control group （P 〈0.05）. The cell viability and △ψm of the quercetin treated group increased （P 〈0.05） and the percentage of apoptotic cells decreased at concentrations of 1-50 umol/L quercetin （P 〈0.01） compared with H2O2 treated group. Conclusion Quercetin can relieve the cell damage and apoptosis from H2O2 induced injury to HaCaT cells by anti-oxidation and mitochondrial protection.     

Endoplasmic Reticulum Stress-mediated Aldosterone-induced Apoptosis in Vascular Endothelial Cells

The aim of this study was to examine the effects of endoplasmic reticulum （ER） stress on aldosterone （Aldo）-induced apoptosis of endothelial cells. Glucose-regulated protein 78 （GRP78） and C/EBP homologous protein （CHOP, a hallmark of ER-associated apoptosis） were used to evaluate ER stress. Western blotting and real-time PCR were used to analyze indicators of ER molecule. Apoptosis was detected by annexin V/propidium iodide staining and flow cytometry. Human umbilical vein endo- thelial cells （HUVECs） were stimulated with different concentrations of Aldo for different durations. Aldo promoted apoptosis of HUVECs and induced ER stress, as evidenced by increased expression of GRP78 and CHOP. siRNA knockdown of CHOP attenuated Aldo-mediated apoptosis. These results in- dicate that ER stress may be involved in Aldo-induced apoptosis of HUVECs.     

Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats

To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride (50 mg/L NaF) and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals (four males and four females). Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L NaF with a low dose of selenium-zinc preparation (0.1 mg/kg Na2 SeO3 and 14.8 mg/kg ZnSO4·7H2O); and group four, 50 mg/L NaF with a high dose of selenium-zinc preparation (0.2 mg/kg Na2 SeO3 and 29.6 mg/kg ZnSO4·7H2O). The activities of serum glutathione peroxidase (GSH-Px), kidney superoxide dismutase (SOD), and the levels of malondialdehyde (MDA) and glutathione (GSH) in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urineγ-glutamyl transpeptidase (γ-GT), inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosis, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.     

Effects of resolvin D1 on inflammatory responses and oxidative stress of lipopolysaccharide-induced acute lung injury in mice

Background A variety of inflammatory mediators and effector cells participate together in acute lung injury,and lead to secondary injury that is due to an inflammatory cascade and secondary diffuse lung parenchyma injury.Inflammation is associated with an oxidative stress reaction,which is produced in the development of airway inflammation,and which has positive feedback on inflammation itself.Resolvin D1 can reduce the infiltration of neutrophils,regulate cytokine levels and reduce the inflammation reaction,and thereby promote the resolution of inflammation.The purpose of this study is to investigate the effects of resolvin D1 on an inflammatory response and oxidative stress during lipopolysaccharide （LPS）-induced acute lung injury.Methods LPS （3 mg/kg） was used to induce the acute lung injury model.Pretreatment resolvin D1 （100 ng/mouse） was given to mice 30 minutes before inducing acute lung injury.Mice were observed at 6 hours,12 hours,1 day,2 days,3 days,4 days and 7 days after LPS was administrated,then they were humanely sacrificed.We collected bronchoalveolar lavage fluid （BALF） and the lung tissues for further analysis.Paraffin section and HE staining of the lung tissues were made for histopathology observations.Parts of the lung tissues were evaluated for wet-to-dry （W/D） weight ratio.tumor necrosis factor （TNF）-α,inter leukin （IL）-1β,IL-10 and myeloperoxidase （MPO） were detected by enzyme-linked immunosorbent assay （ELISA）.A lipid peroxidation malondialdehyde （MDA） assay kit was used to detect MDA.A total superoxide dismutase assay kit with WST-1 was used to analyze superoxide dismutase （SOD）.We determined the apoptosis of neutrophils by Flow Cytometry.A real-time quantitative PCR Detecting System detected the expression of mRNA for heme oxygenase （HO）-1.Results Pretreatment with resolvin D1 reduced the pathological damage in the lung,decreased the recruitment of neutrophils and stimulated their apoptosis.It markedly decreased the expressions of TNF-α,IL-1β and increased the expressions of IL-10,and decreased the production of MDA and increased the expressions of SOD.The mRNA expression of HO-1 was also significantly increased.Conclusions Resolvin D1 displays potent anti-inflammatory actions by regulating cytokines,inhibiting aberrant neutrophil recruitment and stimulating apoptosis of neutrophils.Resolvin D1 can also relieve the injury due to oxidative stress.The mechanisms might be related to increase HO-1 expression.     

Metformin ameliorates insulin resistance in L6 rat skeletal muscle cells through upregulation of SIRT3

Background SIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this process are unclear. Methods The effects of SIRT3 on the regulation of oxidative stress and insulin resistance in skeletal muscle were evaluated in vitro. Differentiated L6 skeletal muscle cells were treated with 750 pmol/L palmitic acid to induce insulin resistance. SIRT3 was knocked down and overexpressed in L6 cells. SIRT3, nuclear factor kappa-light-chain-enhancer of activated B cells （NF-KB） p65, c-Jun N-terminal kinase 1 （JNK1）, and superoxide dismutase 2 （SOD2） were evaluated by Western blotting. Results Over expression of SIRT3 increased glucose uptake and decreased ROS production in L6-1R cells as well as in L6 cells. Knock-down of SIRT3 induced increased production of ROS while decreased glucose uptake in both L6 and L6- IR cells, and these effects were reversed by N-acetyI-L-cysteine （NAC）. Metformin increased the expression of SIRT3 （1.5- fold） and SOD2 （2-fold） while down regulating NF-KB p65 （1.5-fold） and JNK1 （1.5-fold）. Knockdown of SIRT3 （P〈0.05） reversed the metformin-induced decreases in NF-KB p65 and JNK1 and the metformin-induced increase in SOD2 （P〈0.05）. Conclusions Upregulated SIRT3 is involved in the pharmacological mechanism by which metformin promotes glucose uptake. Additionally, SIRT3 may function as an important regulator of oxidative stress and a new alternative approach for targeting insulin resistance-related diseases.     

异氟醚对Aβ25-35诱导大鼠PC12细胞氧化应激损伤的影响及海藻糖的保护作用

目的:探讨吸入麻醉药异氟醚对β淀粉样蛋白25-35(Aβ25-35)诱导大鼠PC12细胞氧化应激损伤的影响,阐明海藻糖对其可能的预防及保护作用。方法:将大鼠PC12细胞随机分为正常对照组(Control组)、异氟醚组(Iso组)、Aβ25-35组(Aβ组)、异氟醚+Aβ25-35组(Iso+Aβ组)、异氟醚+Aβ25-35+海藻糖组(Iso+Aβ+Tre组)和海藻糖组(Tre组)。正常对照组,PC12细胞给予正常细胞培养基培养;Iso组,PC12细胞给予2%异氟醚;Aβ组,PC12细胞给予10 μmol·L^-1 Aβ25-35;Iso+Aβ组,PC12细胞给予2%异氟醚和10 μmol·L^-1 Aβ 25-35;Iso+Aβ+Tre组,PC12细胞给予2%异氟醚、10 μmol·L^-1 Aβ25-35和200 mmol·L^-1海藻糖;Tre组,PC12细胞给予200 mmol·L^-1海藻糖。采用MTT法检测细胞存活率;Hoechst 33342荧光染色检测细胞凋亡率;二氯二氢荧光素-乙酰乙酸酯(DCFH-DA)荧光法检测细胞中活性氧(ROS)水平;化学发光法测定细胞中丙二醛(MDA)水平,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)及过氧化氢酶(CAT)活性。结果:与正常对照组比较,Iso组、Aβ组和Iso+Aβ组PC12细胞凋亡率明显升高(P<0.05或P<0.01),细胞存活率明显降低(P<0.05或P<0.01),细胞中ROS和MDA水平(P<0.05或P<0.01)明显升高,细胞中SOD、GSH-Px和CAT活性明显降低(P<0.05或P<0.01);与Iso和Aβ组比较,Iso+Aβ组细胞凋亡率明显升高(P<0.05),但细胞存活率明显降低(P<0.05),细胞中ROS、MDA水平(P<0.05)明显升高,细胞中SOD和GSH-Px和CAT活性明显降低(P<0.05);与Iso+Aβ组比较,Iso+Aβ+Tre组细胞凋亡率(P<0.05)明显降低,细胞存活率明显升高(P<0.05),细胞中ROS和MDA水平明显降低(P<0.05),细胞中SOD、GSH-Px和CAT活性明显升高(P<0.05)。结论:吸入麻醉药异氟醚能够加剧Aβ25-35诱导PC12细胞氧化应激损伤和细胞凋亡,海藻糖能够通过抗氧化和抗凋亡作用拮抗异氟醚的细胞毒性。     

低氧环境下丙泊酚可增加PC12细胞的凋亡

目的 探讨低氧环境下丙泊酚对PC12细胞株凋亡的影响及机制.方法 将PC12细胞接种于培养板中,采用随机数字表法,将其随机分为6组:低氧对照组(CH组)、空气对照组(CA组)和氧气对照组(CO组),对照组加入脂肪乳浓度10 μmol/L.丙泊酚低氧组(PH组)、丙泊酚空气组(PA组)和丙泊酚氧气组(PO组),丙泊酚浓度为10 μmol/L.药物处理完毕后分别放人低氧(5％O2),空气和氧气(35％ O2)环境的细胞培养箱培养,8h后流式检测细胞凋亡情况,检测细胞内ROS水平和细胞SOD酶活力.结果 与CA组比较,PA组细胞凋亡增加,活性氧簇(ROS)升高,超氧化物歧化酶(SOD)活力增强;与CH组比较,PH组细胞凋亡增加,ROS升高,SOD活力增强;与CO组比较,PO组细胞凋亡增加,ROS升高,SOD活力增强;与PA组比较,PH细胞凋亡增加,ROS升高,SOD活力增强;CO组、CA组和CH组上述各指标差异无统计学意义.结论 低氧环境下丙泊酚可通过氧化应激损伤导致PC12细胞凋亡增加.     

人参皂苷Rg1对β淀粉样蛋白诱导细胞凋亡的影响

目的 探讨人参皂苷Rg1对β淀粉样蛋白(Aβ)诱导细胞凋亡的影响及其机制.方法 利用中国仓鼠卵巢瘤细胞系(CHO)采用MTY方法筛选人参皂苷Rgl抗Aβ细胞毒性的有效浓度.通过转染突变型(M146L)PS1基因的CHO细胞(PS1M146L),利用免疫荧光染色、蛋白质免疫印迹方法,探讨人参皂苷Rg1对PS1M146L细胞中Aβ42和凋亡效应基因半胱氨酸蛋白水解酶(caspase-3)活性蛋白表达的影响,通过脱氧核苷酸转移酶介导的dUTP缺口末端标记法和Annexin V-FITC/PI染色流式细胞仪检测,观察人参皂苷Rg1对Aβ促细胞凋亡的影响.结果 加用25、50、100 μmol/L人参皂苷Rg1的CHO细胞活性明显高于未加用组(均P＜0.05).在转染突变型PS1M146L的CHO细胞中,加用人参皂苷Rg1作用24 h后早期细胞凋亡数(10.11.11±0.76)较未加用组(15.01±1.46)少,差异有统计学意义(P＜0.05);同时Aβ42和caspase-3活性片段的蛋白质表达量较未加用组细胞亦不同程度降低(均P＜0.05).结论 人参皂苷Rg1可能通过降低Aβ42生成和降低caspase-3蛋白质表达抑制Aβ诱导的细胞凋亡.     

中药复方更年春含药血清及其主要单体对β淀粉样蛋白所致细胞损伤的保护作用

目的：观察中药复方更年春含药血清及其主要单体成分对β淀粉样蛋白（amyloid β—protein,Aβ）所致肾上腺嗜铬细胞瘤细胞系PC12细胞损伤的保护作用。方法：采用Aβ25-35作用PC12细胞构建阿尔茨海默病（Alzheimer’s disease,AD）细胞模型,相差显微镜观察细胞形态改变。运用中药血清药理学方法制备大鼠更年春含药血清,以四甲基偶氮唑盐法观察更年春含药血清及其主要单体芍药苷、黄连素、知母皂苷AⅢ、淫羊藿苷对体外培养的PC12细胞活力的影响及其拮抗Aβ损伤的作用,采用流式细胞仪观察更年春复方含药血清及复方主要单体对Aβ诱导的PC12细胞凋亡的影响。结果：PC12细胞在Aβ25-35作用后,有活力细胞数目减少,细胞间连接较松,胞浆较暗淡,细胞碎片较多,贴壁细胞欠透明,部分发生皱缩,胞浆中有较多颗粒。Aβ25-35剂量、时间依赖性地抑制PC12细胞的活力。更年春含药血清可以增强PC12细胞活力,不同浓度更年春含药血清培养细胞24、48、72h后,其增强PC12细胞活力均在20％浓度作用最强。更年春复方含药血清及复方主要单体之一的黄连素及主要单体混合液（包括芍药苷、黄连素、知母皂苷A-Ⅲ、淫羊藿苷）均有拮抗Aβ对PC12细胞损伤的作用,且均能抑制Aβ诱导的PC12细胞早期凋亡,其中更年春含药血清作用最强,中药单体混合液作用其次,而单体黄连素作用最弱。结论：更年春对AD细胞模型有保护作用,其含药血清作用强于主要中药单体及主要单体的混合液。     

鹿茸多肽联合GDNF基因修饰的雪旺细胞对Aβ25-35诱导脊髓神经元凋亡的保护作用

目的：探讨鹿茸多肽（VAP）联合胶质细胞源性神经营养因子（GDNF）基因修饰的雪旺细胞（SCs）对β淀粉样蛋白25-35（Aβ_25-35）诱导的脊髓神经元凋亡的保护作用,阐明其作用机制。方法：制备胎鼠脊髓细胞,取对数生长期的脊髓神经元,采用Aβ_25-35诱导脊髓神经元凋亡,将脊髓神经元分为正常细胞组（正常脊髓神经元）、诱导凋亡组（Aβ_25-35诱导凋亡后的脊髓神经元）、SCs组（Aβ_25-35诱导凋亡后的脊髓神经元+SCs）、GDNF组（Aβ_25-35诱导凋亡后的脊髓神经元+GDNF）、SCs+GDNF组（Aβ_25-35诱导凋亡后的脊髓神经元+GDNF转染的SCs）和VAP联合组（Aβ_25-35诱导凋亡后的脊髓神经元+VAP联合GDNF转染的SCs）。流式细胞术检测各组脊髓神经元凋亡率,免疫组织化学染色检测各组脊髓神经元中caspase-3阳性细胞数。结果：胎鼠脊髓神经元悬液接种后初始脊髓神经元大多为圆形。流式细胞术检测,与诱导凋亡组比较,SCs组、GDNF组、SCs+GDNF组和VAP联合组脊髓神经元凋亡率降低（P<0.05）;与SCs+GDNF组比较,VAP联合组脊髓神经元凋亡率明显降低（P<0.05）。免疫组织化学检测,各组脊髓神经元中均有caspase-3表达,SCs组、GDNF组和SCs+GDNF组细胞着色差异不明显,脊髓神经元中caspase-3阳性细胞数差异不大,但与诱导凋亡组比较明显减少（P<0.05）。结论：VAP联合GDNF转染的SCs对脊髓神经元凋亡有保护作用,该作用通过下调脊髓神经元中caspase-3表达来实现。     

Propofol may protect PC12 cells from induced apoptosis through the signaling pathway

Background There are two major pathological hallmarks of AIzheimer's disease.One is the progressive accumulation of beta-amyloid (Aβ) in the form of senile plaques; the other is hyperphosphorylated tau,causing neuronal apoptosis.Some inhalation anesthetics,such as isoflurane and desflurane,have been suggested to induce Aβ accumulation and cause AD-like neuropathogenesis.Whether intravenous anesthetics have similar effects is still unclear.We therefore set out to determine the relationship between propofol and AD-like pathogenesis.Methods PC12 cells were cultured in serum-free medium for 12 hours prior to drug treatment.Various concentrations from 5 μmol/L to 80 μmol/L of aggregated Aβ25-35 were added to determine a proper concentration for further study.After exposure to 10 μmol/L Aβ25-35 alone or with 20 μmol/L propofol for 6 hours,PC12 cell viability was determined by MTT assay.Western blotting and immunocytochemical staining were performed to observe the protein expression of the Bcl-2 family,tau phosphorylation at different sites,and tau protein kinases and phosphatases.Results Aβ25-35 induced a decrease in PC12 cell viability in a dose-dependent manner.Exposure to 10 μmol/L Aβ25-35 for 6 hours resulted in the mild cell survival,accompanied by a decline in Bcl-2,and an increase in phosphorylation of GSK-3β and tau at different sites.Compared with the Aβ25-35 group,cells treated with propofol alone showed no significant difference,while cells co-incubated with propofol and Aβ25-35 showed a significantly higher survival rate (P ＜0.01 or P ＜0.05).Tau phosphorylation at Ser396,Ser404 and Thr231 and the level of GSK-3β in PC12 cells increased after exposure to 10 μmol/L Aβ25-35.Co-incubation with propofol attenuated cellular apoptosis by inhibiting tau phosphorylation.Conclusions These data indicate that propofol may protect PC12 cells from Aβ25-35-induced apoptosis and tau hyperphosphorylation through the GSK-3β pathway,therefore it may be a safer anesthesia for AD and elderly patients.     

异氟醚对β淀粉样蛋白诱导的大鼠PC12细胞凋亡和内质网应激的影响及其机制

目的：探讨异氟醚对β淀粉样蛋白（Aβ）25-35诱导的大鼠PC12细胞凋亡和内质网应激（ERS）的影响,并阐明其作用机制。方法：将PC12细胞随机分为正常对照组、10 μmol•L-1Aβ25-35组（Aβ组）、2%异氟醚组（Iso组）和2%异氟醚联合10 μmol•L^-1 Aβ25-35组（Iso+Aβ组）。MTT法检测各组PC12细胞存活率;Hoechst 33342核染色法检测各组PC12细胞凋亡形态;Western blotting法检测各组PC12细胞内质网分子伴侣葡萄糖调节蛋白78(GRP78)、ERS相关凋亡信号蛋白C/EBP同源蛋白(CHOP)、磷酸化氨基末端蛋白激酶(p-JNK)和caspase-12表达量。结果：与正常对照组比较,Aβ组和Iso组PC12细胞存活率明显降低（P<0.05）,细胞凋亡率明显增加（P<0.05）,GRP78表达量明显上调（P<0.05）,ERS相关凋亡信号蛋白CHOP、p-JNK和caspase-12表达量均明显增加（P<0.05）;与Aβ组比较,Iso + Aβ组PC12细胞存活率明显降低（P<0.05）,细胞凋亡率明显增加（P<0.05）,GRP78、CHOP、p-JNK和caspase-12表达量均明显增加（P<0.05）。结论：异氟醚能够促进Aβ25-35诱导的大鼠PC12细胞凋亡,其机制与激活ERS及其相关的凋亡信号通路有关联。     

金丝桃苷对高糖诱导的心肌细胞氧化应激损伤的影响及其机制研究

目的 探索金丝桃苷在高糖诱导的心肌细胞氧化应激损伤中的作用及其分子机制。 方法 高糖处理模拟心肌细胞氧化应激损伤。细胞分为5个组:正常对照组（5.5 mmol/L葡萄糖）,高糖损伤模型组（35 mmol/L葡萄糖）,低、中、高浓度金丝桃苷保护组（35 mmol/L葡萄糖+4/8/20 nmol/L金丝桃苷）。各组细胞培养48 h后,CCK-8检测细胞存活力;流式细胞术分析细胞凋亡;通过流式细胞仪利用活性氧（ROS）检测试剂盒DCFH-DA分析ROS水平;超氧化物歧化酶（SOD）和丙二醛（MDA）试剂盒检测SOD和MDA水平;Western blot法检测磷脂酰肌醇3-激酶（PI3K）、蛋白激酶B（AKT）、磷酸化（p）-AKT、核因子E2相关因子2（Nrf2）、p-Nrf2的表达;免疫荧光染色分析AKT的活化情况。 结果 与正常对照组比较,高糖损伤模型组细胞存活率降低,细胞凋亡率增高,ROS、MDA水平升高,SOD水平降低,PI3K相对表达量及AKT、Nrf2磷酸化水平（p-AKT/AKT和p-Nrf2/Nrf2的比值）降低,AKT阳性细胞数比率降低,以上差异均有统计学意义（P<0.05）。与高糖损伤模型组相比,金丝桃苷保护组（4、8、20 nmol/L）细胞存活率升高,细胞凋亡率降低,ROS、MDA水平降低,SOD水平升高,PI3K相对表达量及AKT、Nrf2磷酸化水平升高,AKT阳性细胞数比率升高,以上差异均有统计学意义（P<0.05）。 结论 金丝桃苷可通过激活PI3K/AKT/Nrf2信号通路保护心肌细胞免受高糖诱导的氧化应激损伤。     

A Novel Antisense Oligodeoxynucleotide Targeting Caspase-3 mRNA Prevents PC-12 Cell Apoptosis Induced by Aβ_(25-35)

Ａｌｚｈｅｉｍｅｒ ｓｄｉｓｅａｓｅ (ＡＤ) ,ａｐｒｏｇｒｅｓｓｉｖｅｎｅｕｒｏｄｅｇｅｎｅｒａｔｉｖｅｄｉｓｏｒｄｅｒ,ｉｓｃｈａｒａｃｔｅｒｉｚｅｄｎｅｕ ｒｏｐａｔｈｏｌｏｇｉｃａｌｌｙｂｙｎｅｕｒｏｔｉｃｐｌａｑｕｅ ,ｎｅｕｒｏｆｉｂｒｉｌ ｌａｒｙｔａｎｇｌｅｓ,ａｎｄｓｅｌｅｃｔｉｖｅｎｅｕｒｏｎａｌｌｏｓｓ[1] .Ｎｅｕ ｒｏｎａｌａｐｏｐｔｏｓｉｓｉｓｔｈｅｃａｕｓａｔｉｖｅｆａｃｔｏｒｏｆｎｅｕｒｏｎｓｌｏｓｓａｎｄｎｅｕｒｏｐａｔｈｏｇｅｎｅｓｉｓｉｎＡＤ .Ｃａｓｐａｓｅｓａｒｅｒｅｓ…